Fixing devices

ABSTRACT

A device for securing a workpiece to a pallet for a machining operation, the device being operated from its side between the workpiece and the pallet to secure and release the workpiece so that an access hole to the device through the workpiece is unnecessary; the device may therefore engage in a blind hole in the underside of the workpiece.

United States Patent [56] References Cited UNITED STATES PATENTS 1,438,250 12/1922 Lyon 269/309 1,806,887 5/1931 Bruno 269/53 Primary Examiner-Andrew R. Juhasz Assistant Examiner-Donald D. Evenson Att0rneysEmory L. Groif and Emory L. Groff, Jr.

ABSTRACT: A device for securing a workpiece to a pallet for a machining operation, the device being operated from its side between the workpiece and the pallet to secure and release the workpiece so that an access hole to the device through the workpiece is unnecessary; the device may therefore engage in a blind hole in the underside of the workpiece.

10 7 13 24 5 15 I, I 3 2 76- I r 1 E PATENTEuFaazslsn 355541 SHEET 3 BF 5 FIXING DEVICES This invention relates to improvements in fixing devices, for example for securing workpieces for machining operations.

In US. application Ser. No. 718,887 there is disclosed a device for fixing a workpiece to a support element comprising a member having an external screw thread and an internal hexagonal recess in which a key can'be inserted to rotate the member, the member being fitted in the support element and a spring being provided to urge the member to project fromthe support element. By this device the member can be fitted in the support element from one side thereof, and screwed into a workpiece, to be fixed to the opposite side of the support element when the one side is inaccessible, by insertion of a key through a tapped fixing hole through the workpiece and into the recess to rotate the member sothat it threads into the hole in the workpiece, thereby securing the workpiece to the support element. The provision of fixingholes through a workpiece may, in some circumstances, be undesirable.

According to the present invention, there is provided a fixing device for use infixing a piece,. such as a workpiece, to a support, comprising a member for fitting in the support and arranged to project in a direction from one'side of said-sup? port, the member being adapted to secure the piece to, or release the piece from, said support by movement of said: member relative to the piece, and operable means to receive an element, such as a key, moved into engagement therewith along an axis transverse, and preferably perpendicular, to the aforementioned direction, the means being operable by the element to effect movement of the member to securev the piece to, or release the piece from, said support.

The invention further provides a fixing. support-device for securing a piece, such as a workpiece, comprising a support; a. member fitted in the support and arranged to project in a direction from one side of the support, the member being adapted to secure the piece to, or release the piece from,,thesupport by movement of the member relative to. the piece, and operable means to receive an element, such as a key, moved into engagement therewith along. an axis transverse, and preferably perpendicular to the aforementioned direction, the means being operable by the element to effect movement of the member to secure the piece to, or release the piece from, the support, and the support providing access for the element to the operable means along the axis.

By this arrangement a workpiece having a blindfixing hole, i.e. a recess or hole in one surface of and extending only part way through the workpiece, can be secured to the supportby entry of the projecting part of said member in the hole or recess, and can be secured to or releasedzfrom the support: by movement of the member through operation of'the operable means.

Still further, the present invention provides a support and fixing arrangement for aworkpiece comprising a pallet, at least one support fixed to the pallet, a member fitted in the support and arranged to project in'a direction from the side of the support opposed to the side adjacent the pallet, the; member securing the workpiece to, or releasing the workpiece from, the support by movement of the member relative to the.

workpiece, eg in a blind hole provided in the workpiece, and operable means to receive an element, such as a key, moved into engagement therewith along an axis perpendicular to the aforementioned direction, the meansbeing operable by the element to effect movement of the member to secure the workpiece to, or release the workpiece from, the support, and the support providing access for the element to the operable means along the axis.

The member may be arranged to rotate to effect securing'or releasing of the piece, e.g. the workpiece, and may have an external thread adapted to screw into an internal thread in a hole, e.g. a blind hole, in the piece. Resilient means, such asa spring, may be provided to'urge the member to project from to enter a noncircular shapedhole in the piece, the member having externally threaded parts adapted to interfere with the side walls of the hole on rotation of the member to effect partial tapping-of the hole and thereby secure the piece to the support.

The member may have associated flexible means to grip against the wall of a hole in the piece on movement of the member in the aforementioned direction, or in a direction opposed to that direction. v

Movement of the member may be effected by means of a wormwheel'connected to the member, and a worm operative to turn the wormwheel and having a recess, such as a hexagonal keyway, to receive an element, such asa key, by which the worm can be rotated. The wormwheel may be connected to the member so that rotation of the wormwheel causesrota: tion of the member, or alternatively so. that rotation of the wormwheel causes movement of the member in the aforementioned direction, or in a direction opposed to that direction.

A plurality of such fixing devices maybe arranged, e.g. in one support, with the aforementioned axes alignedso that the element can pass through the operable means of one device to engage with the operable, means of another device. A plurality of such fixing support devices may be arranged, e.g. fixed toa pallet; with the aforementioned axes, aligned, the supports being adapted to permit the element to pass through one support to engage with the operable meansin another support.

Fixing 'devices in accordance. with theinvention will now be described, by way of example, with reference to the. accompanying drawings,.in which: v

FIG. 1 is a plan view of part of a pallet having two supports fixed thereto and with a workpiece shown in broken line,

fixed to the supports,

FIG. 2 is a section on the line II-Il'of FIG. 1, FIG. 3 shows a key, FIG. 4 is a plan view of part of a" pallet: having a support fixed thereto. and with a workpiece, shown in broken line, fixed to the support,

FIG. 5 is a plan view of part of a pallet having a support fixed thereto and. with a workpiece, shown in broken line, fixed to the support,

FIG. 6 isa section onthe line VI-VIof FIG. 5,

FIGS. 7, 8 and9 show differentshapes of holes in awork piece andparts of cooperating.fixingdevices,

FIG. 10 is a section through a workpiece'and fixing device, and

FIGS. ll, 12. and 13 are sections through. workpieces and additional fixing devices.

FIG. 1 shows-a pallet 1 having tapped holes 2 arranged, at the junctions of a square-grid, and having'two supports 3 and 4 fixed to the pallet by means of screws 5 passing through holes 6 in the. support and'threadedinto tapped holes 2, as described in the aforementioned application.

Referring now also to FIG. 2, each of the supports 3 and 4:

' has a raised support surface 7 at. its upper'side, i.e. the side opposed to that adjacent the pallet 1. Projecting through a hole in the support surface in-a directionnormal thereto, i.e. vertically, is a member 8 having an externally threaded upper portion 9 and slidably mounted on a hexagonal shaft 10 whose lower end carries a wormwheel 11. A spring 12 around the shaft 10 urges the member 8 upwardly, the member having a lower flanged portion 13 which can abut against a shoulder I4 provided by the support 3 to limit upward movement of the. member.- A washer 15 is provided between the lower end of the spring 12 and the wormwheel 11. The latter being positioned in. an annular groove 1'6 in the support 3 in which the: wormwheel shaft-and member are-housed.

Also housed in the support 3 is a worm 17- whose axis is horizontal, i.e. perpendicular to the direction in which the member 8 projects from the. support 3, andwhich is located so that its thread meshes with the wormwheel 11. The worm 1.7-

has a central axial hole-or keyway 18 of hexagonal cross section and the support 3 is provided with a through hole E9.

the support. The member may be of noncircular cross section (FIG. 1) running axially; of the wonn l7 and providing access to the keyway 18. A key 20, shown in FIG. 3, having a head 21 of hexagonal cross section to fit the keyway 18, and a handle 22 can thus be inserted through the hole 19 to engage the head 21 in the keyway 18, and rotated to effect rotation of the worm 17. Rotation of the worm 17 about its horizontal axis effects rotation of the wormwheel 11 about its vertical axis, and hence of the shaft and member 8.

In use, a workpiece 23 to be secured to the pallet 1 for a machining'operation is provided with an internally threaded blind hole 24 (Le. extending only part way through the workpiece) suitably located in the surface which is to lie on the support surface 7. The workpiece is then placed on the support 3 so that the blind hole 24 registers with the member 8, the workpiece depressing the member down into the support against the action of the spring 12. The key 20 is then inserted and used to rotate the worm 17, and hence the member 8, so that the upper threaded portion 9, urged upwardly by the spring 12, screws into the blind hole 24 until the flange l3 abuts the shoulder 14. The workpiece is thus secured to the support. To release the workpiece the key 20 is used to rotate the worm 17 in the opposite direction, thereby unscrewing the threaded portion 9 from the blind hole 24.

The support 4 is identical to the support 3 described above and shown in FIG. 2, and the two supports can be fixed to the pallet l with their access holes l9,aligned, as shown in FIG. 1. By this arrangement the key 20 can pass through the hole 19 and keyway 18 of the worm in the near support 4 (the hole 19 extending right through the support) to enter the hole 19 and keyway 18 of the worm in the far support 3, the key 20 being shown in broken line in this position in FIG. 1. Thus the key 20 can be used to secure the workpiece 23 to one support, and then to secure the workpiece to the other support.

The supports 3 and 4 are shown in FIG. 1 only by way of illustration and example, and it will be appreciated that various different forms of supports may be provided according to requirements, the supports being fixable to the pallet in a large variety of positions as described in the'aforementioned application. In particular, a support mayhave more than one raised support surface, there being a fixing device of the form described above associated with and adapted to project from each support surface if required. In this case the axes of the worm associated with two (or more) support surfaces may be aligned so that a key can pass throughthe keyway of one worm to reach a further worm.

FIG. 4 shows fixed to the pallet 1 part of a support 25 having at least two raised support surfaces 26 and 27. A fixing device is associated with each of the support surfaces 26 and 27, and the axes of their associated worms, indicated as 28 and 29 respectively, are aligned with common access hole 30, which extends through the support. The key 20 can thus pass through the keyway in the worm 29 and through the hole 30 to engage its head 21 in the keyway of the worm 28. Worm 28 can then be rotated to secure a workpiece 31 (provided with suitably located blind holes) to the support surface 26, after which the key 20 can be partially withdrawn to engage its head 21 in the keyway of the worm 28 and rotate the latter, thereby securing the workpiece 31 to the support surface 27, after which the key can be withdrawn. The workpiece 31 can be released from the support surfaces 26 and 27 by a similar procedure, the worms being rotated by the key in the opposite direction.

FIGS. 5 and 6 show fixed to the pallet 1 a support 32 of the same general shape and configuration as the supports 3 and 4 previously described, and having a single raised support surface 33, but housing a different form of fixing device. The support 32 houses a worm 34, with acentral hexagonal keyway 35, and whose thread meshes with a wormwheel 36, in a manner as described above. A member 37 is connected to the wormwheel for rotation therewith and projects vertically through the support surface 33. The member 37 has a head 38 of noncircular cross section, the actual shape being best shown in FIG. 7. The head 38 has three equispaced flats 39 between which there are arcuate parts 40 having external screw threads; in other words it can be considered as an externally threaded screw originally of circular cross section but on which the flats 39 have been ground.

The head 38 is adapted to be received in a non circular, plain (ie not threaded) blind hole 41 provided at the desired position in a workpiece 42 to be secured to the support. The hole 41 is slightly larger but of the same shape as the head 38, as can be seen from FIG. 7. Thus the workpiece can be placed on the support surface 33 so that the blind hole 41 registers with the head 38, the latter being oriented to fit and enter the hole in the manner illustrated in FIG. 7. The head 38 can then be rotated by insertion of the key 20 through an access hole 43 in the support 32, so that the key's head 21 engages in the keyway 35 as previously described. As the head 38 rotates in the hole 41 the threaded parts interfere with the sidewalls of the hole and cut into these walls to effect partial tapping of the hole. The head 38 is thus rotated through 60 until it occupies the position shown in FIGS. 5 and 6 and, due to this tapping action, the workpiece is securely held to the support.

The workpiece can be released from the support by use of the key 20 to rotate the head 38, either in the same direction as previously or in the opposite direction, a further 60 to reorient the head with the hole, whereby the workpiece can simply be lifted from the support.

If desired, the member 37 instead of having a head 38 of larger diameter than the member as shown in FIG. 6 may have a head 44 of smaller diameter as shown in FIG. 10, the hole in the workpiece then having an inner part shaped as described above to fit the head 44, and an outer (lower as viewed in FIG. 10) part 45 of circular cross section adapted to fit over the projecting circular portion of the-member 37 to facilitate location of the workpiece on the member.

It will be appreciated that the shape shown in FIG. 7 of the head 38 and the hole 41 is given only by way of illustration and example and that any other suitable shape for either the head or the hole may be used. The shape of the hole need not necessarily be the same as that of the head, the requirement being simply that the head should readily enter the hole and on rotation should interfere with the sidewalls of the hole.

A further example of a possible shape of head and hole is shown in principle in FIG. 8, where the head has two flats 46 and two arcuate externally threaded parts 47, the hole being shown as having the same shape as the head. In practice the hole for this shape of head preferably has arcuate incuts 48 as shown in FIG. 9 to accommodate the inner diameter of the threaded parts 47.

FIGS. 11, 12 and 13 show additional forms of fixing devices. FIG. 11 shows a support 49 having a raised support surface 50 and housing a wonn 51, rotatable about a horizontal axis and having a central hexagonal keyway 52, which meshes with a wormwheel 53 rotatable about a vertical axis as previous described. The wormwheel 53 has a central, internally threaded hole through which a member 54, having an externally threaded lower portion 55, passes. The member 54 is held against rotation by a lower part 55a of square cross section fitting in a corresponding square hole in the support, so that rotation of the wormwheel causes upward or downward movement of the member 54 through coaction of the threads on the portion 55 and in the wormwheel.

The member 54 projects vertically from the support surface 50 and has a partial conical head 56 reducing in diameter to that of the middle portion of the member. Around the member is a flexible longitudinally split sleeve 57 of spring steel whose upper portion is recessed to receive the head 56, and which projects from the support surface 50. The projecting portion of the sleeve 57 and the head 56 are received in a blind hole 58 provided in a workpiece 59 to be secured to the support. After the hole 58 in the workpiece is placed over the sleeve 57 and head 56 the key 20 is inserted into the keyway 52 as previously described and used to rotate the worm 51 and hence wormwheel 53 so that the member 54 moves downwardly. The action of the head 56 on the split sleeve 57 forces the parts of the latter outwardly to grip against the sidewall of the hole 58 and thereby hold the workpiece to the support.

The workpiece can be released from the support by using sure on the sleeve 57.

The fixing device shown in FIG. is essentially similar to that of FIG. 11 except that the member has a partial conical 7 head 60 whose diameter decreases from that of the middle portion of the member, and base: surrounding split sleeve 61 1 whose upper portion is correspondingly shaped so that upward movement of the member forces the parts of the sleeve outwardly to grip against the sidewall of a blind hole in a workpiece, and downward movement of vthe'niember relieves the pressure on the sleeve. The sleeve 61' isretained in the support by an internal shoulder in the support engaging against an extemal shoulder on the sleeve;

The fixing device shown in FIG 13 has a member 62 which can be moved up and down in a'support 63 having a support surface 64 from which the member 62 projects, in a manner as described with reference to FIG. 11. The member 62 has a flanged head 65 and ,is surrounded by a rubber bushing 66 which is sandwiched between the head and a shoulder 67 raised from the support surface Downward movement of the head 65 effects deformation of the bushing 66 so that it grips against the sidewall of a blind hole 68 provided in a workpiece 69 to secure the workpiece to the support. Upward movement of the head 65 relieves thepressure on the bushing 66 thereby releasing the workpiece.

Weclaim: v g Y 1. A fixing support-device for securing a workpiece to a baseplate for the workpiece to be machined, comprising a sup port housing having a raised support surface parallel with the surface of the baseplate on which the workpiece is to rest and fixing means for securing the opposite side of the housing to I the baseplate, workpiece gripping means retained in the-housing and having an end protruding through the support surface, a worrnwheel retained in the housing with its central plane parallel with the surface of the baseplate and the support surface and rotatable. tomove the workpiece gripping means to grip the sidewall of a hole in theworkpiece into which the protruding part of the workpiece gripping means is inserted, an a worm in the housing with its axis parallel with the surface of the baseplate and in engagementwith the wormwheel to rotate it, the worm having an axial keyway to receive a key at the side of the housing between the workpiece and the baseplate to rotate the worm. 

1. A fixing support device for securing a workpiece to a baseplate for the workpiece to be machined, comprising a support housing having a raised support surface parallel with the surface of the baseplate on which the workpiece is to rest and fixing means for securing the opposite side of the housing to the baseplate, workpiece gripping means retained in the housing and having an end protruding through the support surface, a wormwheel retained in the housing with its central plane parallel with the surface of the baseplate and the support surface and rotatable to move the workpiece gripping means to grip the sidewall of a hole in the workpiece into which the protruding part of the workpiece gripping means is inserted, an a worm in the housing with its axis parallel wiTh the surface of the baseplate and in engagement with the wormwheel to rotate it, the worm having an axial keyway to receive a key at the side of the housing between the workpiece and the baseplate to rotate the worm. 